JPS6122633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for advantageously producing a hot-melt resin laminate cloth for use as a base material for adhesive tapes.

Specifically, after forming a thin liquid film that is releasable to hot melt resin such as silicone emulsion on the surface of the pressure roll that comes into contact with the rotating cooling drum of a commonly used laminating machine, This invention relates to a method for efficiently producing a hot-melt resin laminated cloth by continuously supplying a hot-melted resin material to the gap between a drum and the roll while passing a coarse woven cloth or warif through the gap. be.

Now, as a conventional method for manufacturing polyethylene laminate cloth used as a base material for adhesive tapes, there is a method in which a laminating machine is used to heat the polyethylene resin to 300°C or higher to bond it to the cloth in order to sufficiently laminate the polyethylene to the cloth. Kosho 50
- Disclosed in Publication No. 4770. However, in this method, a fabric with a high fiber density such as 100 fibers is selected (a number used in the industry to express the fiber density of cloth, expressed as the sum of the length and width of each inch (25.4 mm)). Even when used, the major drawback was that the molten polyethylene adhered to the pressure roll surface through the fabric's grains, causing adhesion between the roll and the fabric, making lamination difficult or impossible. . Furthermore, a method has also been proposed in which a coarse woven fabric and a polyethylene film are laminated together and a polyethylene coating is applied. However, the base material obtained by this method has weak adhesive strength between polyethylene and cloth, and when used as a base material for adhesive tape, wrinkles occur due to lifting of the film surface when unwinding, and the film only However, this method was not entirely satisfactory, as it had the disadvantage that it easily peeled off, impairing the properties of the cloth adhesive tape.

The present inventor believes that if it is possible to prevent the molten polyethylene from adhering to the pressure roll surface through the fabric grains and thereby causing adhesion with the woven fabric in the conventional method, We thought that it would be possible to effectively perform lamination using coarse fabrics without using densely woven fabrics, and we used a method of peeling polyethylene or other heat-melted resin on the surface of the presser roll of the laminating machine. We have continued to study methods for forming thin liquid films with properties. As a result, after forming a thin releasable liquid film such as silicone emulsion on the surface of the pressure roll, the rough fabric is passed through the gap between the cooling drum and the pressure roll of the laminating device. When laminating was performed by continuously supplying hot melted resin such as molten polyethylene into the gap, as expected, no adhesion occurred between the presser roll surface and the fabric surface, and the laminating process was completed. This was done extremely effectively.
Furthermore, it has been confirmed through numerous experiments that when the thus obtained laminate cloth is used as an adhesive tape base material, no floating wrinkles occur on the surface of the laminate film when the tape is unwound. The present invention has now been completed based on the above experimental results.

If the method of the present invention is applied to the production of hot-melt resin laminated cloth, it is possible to efficiently produce, for example, uniform polyethylene laminate cloth from coarse woven fabric, and if the laminate cloth is used to manufacture adhesive tape, it is possible to efficiently produce a uniform polyethylene laminate cloth from coarse woven cloth. There is no fear that the polyethylene will peel off when unwinding, unlike conventional methods. Therefore, the method of the present invention is considered to be an invention that provides an extremely effective method for producing laminated cloth from not only the above-mentioned polyethylene resin but also other hot melt resins such as polypropylene and polyester.

To further explain the present invention, the coarse woven fabric used in the present invention has a length of 30 pieces/25.4 mm and a width of 15 pieces.
A thickness of about 25.4 mm is preferable, and the releasable thin liquid film formed on the pressure roll surface of the laminating device must be one that evaporates at the melting temperature of polyethylene or the like. Practically speaking, a thin film of 0.1 mm or less gives good results. Further, as a chemical for forming a thin film, a 0.6% silicone emulsion is suitable, but it is also effective to use other substances with the same effect, such as an aqueous solution of a surfactant. Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

EXAMPLE In order to facilitate understanding of the method of the present invention, a peelable thin liquid was put into the storage tank of the laminating apparatus used, and the thin film was formed on the presser roll surface, and the rough fabric was fed through the apparatus. A schematic cross-sectional view of the main parts of the figure is shown.

In the figure, 1 is a cooling drum equipped with a cold water circulation device inside, 2 is a pressure roll, 3 is a back-up roll, 4 is a storage tank, 5 is a stripping liquid,
Reference numeral 6 indicates a T-die for extruding molten polyethylene, 7 indicates a peelable thin liquid film formed on the pressure roll surface, 8 indicates a coarse woven fabric, and 9 indicates a polyethylene-coated fabric.

To explain the manufacturing method of polyethylene laminate cloth with reference to the figure, first, the release liquid of the present invention (0.6% silicone emulsion) is placed in the storage tank 4.
After that, the back up roll 3 is adjusted to form a peelable thin liquid film 7 of 0.1 mm or less on the surface of the pressure roll 2. Once this membrane format is completed, lamination is started and coarse woven fabric 8 (30 lengths/
25.4mm, 15 width/25.4mm gauze) to 310
Polyethylene melted at a temperature of
The laminated cloth of the present invention can be obtained by cooling and winding the cloth while contacting with the cloth. A prototype adhesive tape was made by applying a rubber adhesive to the laminated cloth obtained in this way, and its adhesive strength was measured according to JIS Z0237, and it was found to be 1.5 kg/25 mm. The film was strong and had no lifting or peeling.

[Brief explanation of the drawing]

The figure is a schematic sectional view showing the main parts of a laminating apparatus for explaining one embodiment of the present invention. 1... Cooling drum, 2... Pressure roll, 7
... Peelable thin liquid film, 8... Coarse woven fabric.

Claims (1)

[Claims] 1. After forming a thin liquid film that is releasable to the hot melt resin on the pressure roll surface that contacts the cooling drum of the laminating device, the hot melt resin is placed in the gap between the drum and the roll. A method for producing a hot-melt resin laminate cloth, characterized in that a coarse woven cloth is passed through the cloth while being supplied.